Chuck



Deca E3, 1938. F. RswANsoN 2,140,303

l CHUCK Filed my 15, 1935 5 sheets-sheet 1 Dec. 13, 1938. y F R. SWANSON 2,140,303

I CHUCK Filed July l5, 1955 I5 Sheets-Sheet 2 M Y M Dec. 13, 1938. P. R. swANsoN 2,140,303

' CHUCK Filed July l5, 1935 3 Sheets-Sheet 3 A E: w

Patented Dec. 13, 1938 UNITED STATES PATENT OFFICE CHUCK Application July 15,

14 Claims.

This invention relates to chucks and has as one object to provide a chuck o1" novel and improved construction capable vof use for single or double end turning.

Another object of the invention is to provide a chuck of the character described which is easily and quickly actuated and locked in workclamping posi-tion and in which the clamping action increases as the lload on the chuck increases.

Another object is to perfect a chuck which is self-equalizing yet which when locked in workclamping position becomes non-floating without distorting the work piece.

A further object is to provide a chuck having a single means requiring movement through a small arc only for rendering the jaw locking means ineffective and for withdrawing the jaws.

Still a further object is to .provide a chuck having jaws and manual means for actuating the same, and locking means for the jaws initially spring actuated and finally manually actuated to complete the locking by relative angular movement of the chuck body and the jaws.

Yet a further object is to provide la chuck having* a body, radially movable jaws .having cam surfaces on their outer ends, a cam plate for moving the jaws radially, rollers individually spring-pressed between the body and the outer end of the jaws to lock the same in work-clamping position, and means supporting the jaws for angular movement relative to the body to permit wedging of the rollers in locking position.

Other objects and advantages will become apparent from the following description, taken in connection with the accompanying drawing, in

which:

Fig. l is an end view partially in elevation an partially in section of a chuck embodying the features of this invention. The chuck is shown with the jaws engaging the work but not locked in work-clamping position.

Fig. 2 is an axial section taken along line 2-2 of Fig. 1. Wrench sockets are shown though not actually on the section line.

Fig. 3 is an axial section taken along line 3 3 of Fig. 1.

Fig. 4 is a fragmentary detail view taken along line lll-Jl or" Fig. l.

Fig. 5 is a fragmentary view partially in elevation and partially in section showing the chuck with the jaws in fully retracted position.

Fig. 6 is a fragmentary view partially in elevation and partially in section showing the jaws locked in work-clamping position.

193'5, Serial No. 31,315

While the invention is susceptible of various modifications and alternative constructions, it is here .shown and will be described hereinafter in a preferred embodiment, but it is not intended that `the invention is thereby to be limited to the specic construction disclosed but it is intended to cover al1 modifications 'and alternative conA structions falling within the spirit and scope of the invention `as defined by the appended claim.

For purposes of disclosure, the chuck is here shown mounted on the end of a hollow flanged spindle I0 and comprises generally a chuck body II, work-clamping means including jaws I2, and means for actuating and locking the jaws in work-clamping position including a cam plate I3 and an 'impact member I4. Hereinafter the end of the chuck adjacent the spindle will be referred to as the rear end or face, while the other end will vbe referred to as 'the front end or face. 'Ihe chuck body II is annular and is composed of an axially extending ilange I5 and a radially inwardly extending flange I 6 making the body generally L-shaped in radial cross section. Preferably 'the radial flange I6 is spaced from the rear face of the chuck body to form an annular shoulder I'I within which is received the flanged end of the spindle III. Bolts I8 having their heads I9 countersunk in the flange I'B lextend through the flange and are threaded into the spindle I0 removably to secure the chuck body to the spindle.

Mounted within the flange I6 of the chuck body for limited rotation relative thereto is a jaw holder 2'!) centrally apertured to permit the projection therethrough of awork piece W which is to be secured in the chuck. The jaw bolder is substantially thicker than the flange I5 and in the portion extending beyond the forward face of the flange is formed with circumferentially spaced radial channels 2l in which the jaws I2 are reciproca'ble. The bottoms of the channels 40 2I are ush with the forward face of the flange I5 (see Fig. 2) to guide the jaws past the flange in their radial outward movement. The jaws I2 are retained in their channels by the cam plate I3 which also serves, among other purposes, to retain the jaw holder against movement in one direction axially of the chuck. To these ends, the came plate I3 is formed with a circumferential flange 2.2 which is engaged by a retaining ring 23 secured by screws 24 to the flange I5 of the chuck body. An annular spacer `25 tting within the flange I5 is interposed between the flange I6 and the cam plate to prevent the latter from binding the jaws or the jaw holder. The spacer 25 forms a cylidrical surface concentric with the axis of the chuck and is constrained to rotate with the chuck body by means of a pin 26 extending through the flange I and into engagement with the spacer. The jaw holder is restricted against movement in the opposite direction axially of the chuck by the spindle I0.

In the present instance three jaws I2 (see Fig. 1) are provided. These jaws are rectangular in transverse and longitudinal cross section and lit slidably within the channels 2| equally spaced angularly. At its inner end, each jaw I2 is provided with a removable tip 30 of hardened material. These tips are of varying thickness so that by the choice of a tip of proper thickness the chuck may be adapted to clamp work pieces of different diameter. Each tip 30 is provided with a tooth 3| for engaging the work piece and with a segment 32 interfitting with a recess 33 in the jaw to carry the strain and permit the tips to be secured by a single bolt 34.

The outer end of each jaw is formed to provide a cam surface 35 of a character such that the length of the jaw increases progressively when traversed in a counter-clockwise direction, as Viewed in Figs. 1, 5 and 6, the chuck being adapted to rotate the work piece in that direction. The length of the jaws is such that when proper tips 36 have been selected and the jaws moved radially inwardly until the teeth 3I on the tips contact the work, the trailing edge of the outer end of each jaw (see Fig. 1) will be inwardly of the periphery of the jaw holder while the leading edge will project beyond the periphery. Preferably the trailing edge is slightly bevelledV at 35. Intermediate its ends each jaw carries a projecting pin 36.

Means is perfected herein for making the chuck self-equalizing yet providing for non-floatingly locking the jaws in equalized position, and for effecting such locking and release of the jaws in a simple, expedient manner. To that end the jaws are reciprocated to and from work-clamping position by a limited rotation of the cam plate I3, which for that purpose is formed with cam slots generally designated 46 into which the jaw pins 36 project. The cam slots 40 extend at right angles to a diameter passing through the center of curvature of the inner end of the slot so that rotation of the cam plate through a small arc in a clockwise direction, as viewed in Figs. 1, 5 and 6, will move the jaws radially from the position shown in Fig. 1 to the fully retracted position shown in Fig. 5. In order that the jaws, when in work-clamping position, may have a limited movement independently of one another and of the cam plate to effect equalization, the inner half 40 of the slot is made slightly wider than the diameter of the jaw pins 36 so as to provide a lost motion connection permitting the independent movement. The remaining portion 40" of the cam slot 40 is substantially equal in width to the diameter of theY jaw pins. At its outer circumference the cam plate I3 is made thick enough to accommodate a series of sockets 42 for the reception of a wrench Y a socket 41 which bears against the roller 44 while at the other end the spring is seated in a similar socket 41 abutting a pin 48 carried by the cam plate I3 and projecting into the raceway 45 in which the roller operates. As best seen in Fig. 5, half of the pin 48 is cut away to provide a at surface against which the socket 41' abuts.

A similar pin 5I) carried by the cam plate and projecting into the raceway 45 is provided for each of the rollers 44 to limit the movement of the roller under the influence of the spring 46 and particularly to withdraw the roller from between the jaw and the spacer 25 in order to permit outward movement of the jaw. Each pin 56 has onehalf thereof cut away to provide a flat surface and is disposed with this surface facing inwardly but rotated in a clockwise direction as viewed in Fig. 1 to a position inclined with respect to a radial line through the pin. This is done in order that the pin 56 may clear the jaw I2 when the cam plate is actuated to withdraw the jaws. Each pin 5U is secured in this position by means of a set screw 5I threaded into the cam plate and partially into the pin.

It Will be apparent from the foregoing that by limited clockwise rotation, as viewed in Fig. 1, the cam plate I3 serves both positively to remove the rollers 44 from locking relation with respect to the jaws by direct engagement of the pins 56 with the rollers 44 and to retract the jaws I2. When the cam plate is rotated in a counter-clockwise direction, it functions to move the jaws radially inwardly into contact with the work piece and impositively urges the rollers into locking relation with respect to the jaws by compressing the springs 46. Thus it is seen that due to the lost motion between the slots 40 in the cam plate and the jaw pins 36, the jaws are self-equalizing and will be capable of securely clamping a work piece, should it be slightly eccentric or out of round, without distorting it. Furthermore, it will be apparent that each roller 44 will initially assume a position entirely dependent upon the position of the jaw with which it is associated.

Final locking of the jaws I2 in equalized workclamping position is effected by rotation of 'the jaws and jaw holder relative to the chuck body I I. Such relative rotation between the jaws and the chuck body causes the rollers 44 to climb to a higher point of the cam surface 35, forcing the jaws into gripping relation with respect to the work and wedging the rollers securely between the jaws and the chuck body. In the present instance rotation of the jaw holder 26 and the jaws I2 relative to the chuck body is imparted by the impact member I4. This member isV provided with an annular flange 55 received in a groove 56 formed in the cam plate I3 and retained in the groove by means of a retaining ring 5? secured to the cam plate by screws 58. About its periphery the impact member I4 is` formed with a series of circumferentially spaced sockets 59 for the reception of a wrench. Rotation of the impact member I4 is imparted to the jaw holder 26 by means of a pin 66 carried by the jaw holder and projecting through an arcuate slot 6I in the cam plate I3 into engagement with the impact member I4. In order that the force transmitted from the impact member to the jaw holder 26 may be in the nature of a sharp blow the member I4 is formed with an arcuate recess 62 into which the pin 60 projects and which is several times longer than the diameter of the pin. Thus it will be seen that the impact member I4 has a limited rotation relative to the jaw holder 20 so that by rotating the 75 impact member in a clockwise direction, as viewed in Figs. 1, 5 and 6, the jaw holder 20`may be given a sharp blow thereby imparting to it a clockwise rotation forcing the rollers 44 into tight wedging relation with respect to thejaws I2 and the chuck body.

For unlocking the jaws, the impact member I4 is not necessary because pins 50 o-n the cam plate directly engage the rollers 44 to loosen them and withdraw them. A pin 63 extends radially through the iiange I 6 ofthe chuck body and projects into a short peripheral groove 64 in the jaw holder 23 to limit the relative rotation between the jaw holder and the chuck body.

Disposed axially in the jaw holder 20 is a sleeve 65 closed at one end by a screw plug 5B and at the other end having an opening dened by an inwardly projecting flange 6l. Slidable within the sleeve 65 and having a reduced portion 68 adapted to project through the opening' defined by the flange 61 is a detent pin 69 urged to projected position by a compression spring 'ID seated at one end in! a recess II formed in the pin and at its other end abutting the screw plug 56. The projecting end 68' of the pin is adapted to engage in a detent socket 12, carried by the cam plate I3, when the plate has been rotated to a position moving the jaws` inwardly into engagement with the work piece. The detent serves to maintain the over travel of the cam plate, i. e., hold it in the position sho-wn in Fig. l with the pins 5i) out of engagement with the rollers 44, until the impact blow of the member I4 has: wedged the rollers in jaw-locking position. The detent also prevents the cam plate from oscillating upon sudden reverses or jogging to prevent unlocking of the chuck by the pins 50 striking the rollers 44. Preferably the cam is cut away to form a groove at 'I3 in which the detent pin rides when the cam plate is swung in a clockwise direction to withdraw the jaws.

The operation of the chuck briefly is as follows: Assuming that the chuck is open, that is that the jaws are in fully retracted position as shown in Fig. 5, a work piece could then be inserted in the chuck. By inserting the customary tool in one of the sockets 42 of the cam plate, the plate would then be rotated in a counterclockwise direction as viewed in Figs. l, 5 and 6. In such rotation the slots 40 would engage the pins 35 of the jaws I2 and cam the same radially inwardly into Contact with the work piece. 'I'he position of the jaws would be determined entirely by the shape of the work piece because of the lost motion between the inner portion 4e of the slots in the cam and the pins 36 so that the chuck would be self-equalizing. Such rotation of the cam plate would also move the pins 55 in a counter-clockwise direction beyond the jaws and would compress the springs 46 and thereby yieldably urge the rollers 44 between the ends of the jaws and the spacer member 25. The jaws and the rollers would then assume the position shown in Fig. l. For the nal locking of the jaws in work-clamping position, the tool YisI inserted in one of the sockets 59 of the impact member I4 and the member rotated rapidly in a clockwise direction. Such clockwise rotation of the member I4 would impart a sharp blow to the jaw holder 26 and the jaws, there-by rotating the same relative to the chuck body causing the rollers 44 to mount to a higher portion of the cam surface 35 and thereby force the jaws downwardly into gripping relation with respect to the work piece and wedging the rollers securely between the jaws and the chuck body, as shown in Fig. 6. 'Ihe chuck is now in operative position and it will be seen that when a load is applied tending to resist rotation of the work piece, the drive is through the rollers 44 and that drive is in a. direction tending to cause further wedging action thus increasing the gripping action of the chuck.

To unlock the chuck for removing the work piece, it is onlyv necessary to rotate the cam plate I3 in a clockwise direction thereby directly engaging the rollers 44 by the pins 50 to loosen the rollers. Continued rotation of the cam plate then withdraws the rollers and the jaws I2.

Thus it will be seen that I have perfected a chuck which has radially movable jaws independently movable and independently locked so as rigidly to clamp an eccentric work piece without distorting the same, such movement and locking of the jaws, however, being effected by movement of a single element; in which the clamping action increases with the load on the chuck, and which is sturdy and readily manufactured and assembled.

I claim as my inventioni 1. A chuck comprising, in combination, a body, a plurality of jaws, a jaw holder rotatable relative to said body, means for moving said jaws radially for clamping or unclamping a work piece, and means interposed between the body and the jaws when in work-clamping position for locking the jaws in clamping position and for transmitting the rotation of the body to the jaws.

2. A chuck comprising, in combination, a body, a plurality of jaws, mea-ns for moving said jaws radially for vclamping or unclamping a work piece, wedge means interposed between the body and the jaws whe-n in work-clamping position for locking the jaws in clamping. position and for transmitting the rotation of the body to the jaws, said wedge means increasing the clamping action of the jaws as: the load on the chuck increases.

3. A chuck comprising, in combination, a body, having an internal cylindrical surface concentric with the axis of the chuck, a plurality of jaws having cam surfaces on their outer ends, means for moving said jaws radially into and out of clamping relation to a work piece, and rollers interposed between the cylindrical surface and the cam ends o-f said jaws wedging said jaws` in work-clamping position and transmitting the rotation of said body to the jaws.

4. A chuck comprising, in combination, a body, a plurality oi jaws, means for moving said jaws radially into and out of work-clamping relation, said means having a lost motion connection with s-aid jaws permitting limited independent movement of the jaws in either direction radially in work-clamping position, yieldable means urging said jaws to Ywork-clamping position to permit self-equalization thereof, and means for nonfloatingly locking said jaws in work-clamping position.

5. A chuck comprising, in combination, a body, a plurality of jaws, means for moving said jaws radially into and out of work clamping relation, s-aid means having a lost motion connection with said jaws, individual jaw-locking and rotationtransmitting means interposed between said jaws and said body, and individual springs urging said last named means into jaw-clamping position.

6. A chuck comprising, in combination, a body, a plurality of jaws, means for moving said jaws radially having a lost motion connection with said jaws to permit self-equalization thereof, rollers adapted to be interposed between said jaws and said body for pressing said jaws into engagement with a work piece and for transmitting rotation of s-aid body to said jaws, and individual springs urging said rollers between said jaws and said body.

7. A chuck comprising, in combination, a body, a plurality of jaws having cam surfaces on their outer ends, means for moving said jaws radially to open or close the chuck having a lost motion connection with said jaws to permit self-equalization thereof, rollers adapted to be interposed between the cam end of said jaws and said body when the chuck is closed for urging said jaws into work-clamping position, individual spring means urging said rollers between said jaws and said body, and means for rotating said jaws relative to said body for wedging said rollers into jaw-locking position. Y

8. A chuck comprising, in combination, a body, a plurality of jaws, a jaw holder rotatable relative to said body providing radial guides for said j-aws, a cam plate rotatable relative to said body and said jaw holder, said plate having a plurality of cam grooves therein, a pin on each of said jaws engaging one of said cam grooves to be moved radially thereby upon rotation of said plate relative to said jaws, a roller interposed between the outer end of each jaw and said body for looking the jaws in work-clamping position and for transmitting the rotation of said body to said j-aws, individual springs urging said rollers between the ends of said jaws and said body, and an impact member for rotating said jaws relative to said body to wedge the rollers in locking position.

9. A chuck comprising, in combination, a body,`

a plurality of jaws radially movable to open or close the chuck, means urged between the ends of said jaws and said body for urging the jaws into clamping Vrelation with respect to a work piece, and a single means for withdrawing said rst mentioned means completely from between said jaws and said body and thereafter moving said jaws radially to the chuck-open position.

10. A chuck comprising, in combination, a body, a plurality of jaws radially movable, rollers adapted to be disposed between the ends of said jaws and said body when the chuck is in closed position, and a cam plate having engagement with said jaws for moving the same radially, and carrying means for positively removing said rollers from between s-aid jaws and said body when opening the chuck, and for yieldably urging the rollers between the jaws and the body when closing the chuck.

l1. A chuck comprising, in combination, a body, a plurality of jaws radially movable, a pin projecting axially of the chuck from each of said jaws, rollers adapted to be interposed between the ends of said jaws and said body when the chuck is in closed position for forcing the jaws into Work-clamping position and for transmitting the rotation of said body to said jaws, a cam plate having cam slots into which said pins project and by which said jaws are moved radially upon rotation of said plate, pins c-arried by said plate and adapted, upon rotation of said plate to withdraw said jaws, to engage s-aid rollers and withdraw the same from between said jaws and said body, a spring for each of said rollers having one end abutting the same, and a pin carried on said cam plate providing an abutment for the other end of said spring.

12. A chuck comprising, in combination, a body, a jaw holder mounted for limited rotation within said body, a plurality of jaws movable radially in said holder and each jaw having a cam surface on its outer end, a pin projecting from each of said j-aws, rollers adapted to be interposed between the ends of said jaws and said body, a cam plate having a plurality of cam slots for receiving the projecting ends of said jaw pins and adapted to move said jaws radially upon rotation of said plate, means carried by said plate adapted upon rotation of the plate in a direction to open the chuck to engage said rollers and positively withdr-aw the Same from between said jaws and said body, and upon rotation in the opposite direction yieldably to urge said rollers between said jaws and said body, an impact member rotatably mounted on said plate having an arcuate recess, said plate having an arcuate slot, and a pin mounted in said jaw holder and projecting through the arcuate slot in said plate into the arcuate recess in said impact member.

13. A chuck comprising, in combination, a body, a plurality of jaws, a jaw holder having limited rotation relative to said body, a cam plate for moving said jaws radially having a lost motion connection therewith, means adapted to be interposed between said jaws and said body for locking the jaws in work-clamping position and for transmitting the rotation of said body to said jaws, and a detent pin and detent socket, one mounted in said cam plate and the other in said jaw carrier and adapted to engage when the chuck is in closed position.

14. A chuck comprising, in combination, a driving body, a plurality of radially movable jaws, a jaw holder mounted within said body for limited rotation relative thereto, and means adapted to be interposed between the body and the jaws when the jaws are in work clamping position for locking the jawsl in clamping position and for transmitting the rotation of the body to the jaws, said means being withdrawable from between the body-and the jaws.

FRED R. SWANSON. 

